Question:
I recently hooked up a 4 pin trailer harness to my 07 Dodge Charger. When I connect the trailer and test the light, the brake, turn, and hazard function stops working and front blinking real fast. I turn the car off and back on and it resets the system until I try to test trailer again. Trailer works fine on other vehicles. Is there extra relays to use or do I have to buy another harness like an oem mopar one?
asked by: Jim C
Expert Reply:
There are a few things that you can check to determine what the problem may be on your 2007 Dodge Charger. First check the connectors for the harness and where they connect to the vehicle. You may find a bent terminal that you can put back into place.
If the trailer has a lot of extra lights then it could be overloading the harness and the electrical system on your 2007 Dodge Charger. The system is rated for a maximum of 1 stop/turn light per side (7.5 amps), and a maximum of tail light power draw of 7.5 amps.
If the trailer has extra lights, it could be created an excessive power draw on the system and could possibly be tripping a circuit breaker which shuts down the system. Turning off the vehicle and restarting it resets the breaker until it is overloaded again.
If you can test the wiring without the trailer connected using a circuit tester like # 3808, and the wiring harness works without the trailer connected, AND the trailer lights are not drawing too much power, then there is a problem on the trailer side that needs to be addressed. But since the trailer works fine with other vehicles, the trailer wiring is probably not the problem.
Start by checking all of the trailer grounds. They will need to be connected to clean and corrosion free and metal surfaces on the trailer frame. Also check the wiring for any frayed, pinched, nicked, or cut wires that may be touching the trailer frame and fix as needed.
If you still are having a problem then you will most likely need a hardwire Modulite that has a higher amperage rating, # 119190KIT.
expert reply by: Michael H

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Products Referenced in This Question
Upgraded Heavy Duty Modulite Circuit Protected Vehicle Wiring Harness with Install Kit
Product Summary:
Trailer Hitch Wiring
Powered Converter
2 Wire System
3 Wire System
Universal Fit
Product Specs:
4 Flat
Product Page this Question was Asked From
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